If you want a simple source of astronomy every day, use APOD: https://apod.nasa.gov/apod/astropix.html  which always has an image with a description written by an astronomer.

The image is not always creative commons licensed, so may not always be used in a DOME presentation, but can certainly be shared with a class for inspiration. Students could be challenged to prepare a very short description of the image, record their own audio and then these could be assembled for sharing in the DOME using images from Stellarium or Nightshade.